Tool drive transfer apparatus



[50] Field of Search United States Patent Julius Harold Bushman Southington, Conn. [2]] Appl. No.' 719,627 [22] Filed Apr. 8, 1968 [45] Patented Dec. 22, 1970 [73] Assignee The Stanley Works [72] Inventor New Britain, Conn. a corporation of Connecticut [54] TOOL DRIVE TRANSFER APPARATUS 9 Claims, 3 Drawing Figs.

[52] 0.5. (I 140/931 [51] Int. Cl. B2 II 9/02 [56] References Cited UNITED STATES PATENTS 2,102,981 12/ 1937 Spencer l40/93.4 2,105,391 1/1938 Almdale 72/446 Primary Examiner-Lowell A. Larson Attorney-Prutzman, Hayes, Kalb & Chilton ABSTRACT: The power drive mechanism in a strapping tool incorporates a releasable interlock adapted to alternatively secure a jaw support member to the drive piston during movement between a retracted position and a work station and to the frame during the strap sealing operation of the jaws. The preferred embodiment of the interlock takes the form of a shiftable roller constantly housed by but protruding from the jaw support member.

TOOL DRIVE TRANSFER APPARATUS BRIEF DESCRIPTION OF THE INVENTION manner while at the same time permitting the work-performing portion to efficiently and directly perform its work function while in the work station.

Another object of the invention is to'provide a powered strap-sealing tool with a new and improved drive interlock mechanism of substantially simplified design, the tool including a sealing assembly drive associated with the interlock mechanism for driving the sealingassembly between its retracted and operative positions and being automatically releasable by the mechanism upon reaching the operative position for directly driving the strapsealing operation.

Another object of this invention is to provide a new and improved drive interlock mechanism for a powered strap-sealing tool of the type described, the mechanism being effective to retain the sealing jaws of the tool in aninoperative condition upon movement of the jaws into and out of a strap-sealing station.

A further object of the present invention is the provision of a drive interlock for a powered tool which features simplified construction, combined operating functions and increased durability and smoothness of operation.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application whichwill be indicated in the appended claims. a

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing:

FIG. 1 is a-side elevation of a strapping tool incorporating the present invention, the tool being partly broken away to show the drive interlock mechanism thereof when the sealing jaws are in a retracted position;

FIG. 2 is a fragmented side elevation similar to FIG. 1 showing the relative location of the interlock mechanism when the sealing jaws are positioned at the work station prior to a sealcrimping operation; and

FIG. 3 is a fragmented side elevation similar to FIG. 2 showing the interlock mechanism during the seal-crimping operation of the tool's operating cycle.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in greater detail, wherein like reference numerals indicate like parts throughout the several FIGS. the invention is shown utilized in a powered strapping tool 10 comprising frame member 12 adapted to rest on a package about which strapping is to be applied and a sealing mechanism, generally designated 14, supported by the frame 12 and adapted to seal overlapping portions of the strapping. The sealing mechanism 14 includes a reciprocating sealing assembly 16 mounted for movement relative to the frame member 12 between a raised or retracted position shown in FIG. 1 and a lowered operative positionillustrated in FIGS. 2 and 3. The sealing assembly 16 includes a conventional fluidactuated piston 18 operable within a cylinder 42 supported atop the frame 12 for movement from its rest position to its extended position for effecting the desired sealing operation. Fixedly connected to the piston 18 and depending therefrom is a piston rod 20 integrally supporting a generally rectangular drive head 22 which in turn is sandwiched between a pair of side support members 24, 26.

The'entire assembly 16 reciprocates as a unit within the frame 12 during its travel between the work station position of FIG. 2 and the retracted rest position of FIG. 1. In the'embodiment illustrated, this is effected by providing the frame 12 with a fixed restraining plate 28 positioned immediately adjacent the support member 26 and in intimate contact therewith, the restraining plate 28 being provided with a shoulder stop 30 projecting inwardly of the frame 12 into a cooperating recess 32 provided on the outer face 34 of the abutting support 26. The recess 32 extends longitudinally of the pistons direction of travel and facilitates reciprocal travel of the entire assembly 16 as it moves out of its rest position, a top terminal edge 38 of the recess 32 cooperating with the shoulder stop 30 to limit downward movement of the support 26 in the manner illustrated in FIG. 2. Thus, as can be seen, during the initial part of the piston's power stroke, it functions to drive the entire sealing assembly 16 out of its rest position of FIG. 1 and into its work station position of FIG. 2 against the bias of the pistons return drive spring 40 housed within the piston cylinder 42.

As mentioned hereinbefore, in accordance with the present invention the tool 10 is provided with a simple, efficient and reliable drive transfer or interlock, generally designated 46, which not only assures that the sealing assembly 16 moves as a unit from its retracted rest position to its work station in an expeditious manner but also provides a facile, automatic release of the drive head 22 of the tool upon reaching the work station so that the full driving force of an uninterrupted drive stroke can be employed to crimp a strapping seal positioned at the work station. It will of course be appreciated that, as shown in FIGS. 1-3, the support member 26 of the sealing assembly 16 is connected to the rotatable sealing jaws 48 of the tool by a pivot pin 50 which not only is fixedly seated within the side support members 24 and 26 but extends through each of the jaws 48 to provide a fixed pivot point about which the jaws may rotate during their seal-crimping operation. The jaws are suitably connected to the driving head 22 by means of the toggle links 54 mounted for rotation on the toggle pin 56 carried on the lower extremity of the drive head 22. Thus, the movement of the sealing assembly 16 as a unit from its rest position to its work station position is accomplished not only through the connection provided by the interlock 46 connecting side support member 26 with the driving head 22 but also through the fixed pivot pin 50. I

The releasable interlock 46 conveniently takes the form of a cylindrical roller 60 of greater diameter than the width of support member 26, the roller being seated within a transversely extending slot 62 in the support member'26 and protruding outwardly therefrom into an arcuate, concave locking notch 64 provided on the side of the drive head 22. As shown, when the assembly 16 is in its rest position, the flat inside face 66 of the restraining plate 28 abuts and covers one side of the slot 62 thereby causing a portion of roller 60 to protrude from the slot and lockably rest within the arcuate notch 64, thus fixedly positioning the support 26 relative to drive head 22. However, the face 66 of restraining plate 28 is also provided with an arcuate, transversely extending recess 68 substantially identical to notch 64. Accordingly, as the assembly 16 is driven out of its rest position, the shoulder stop 30 comes into abutting contact with edge 38 on the support 26 bringing recess 63 into registry with the roller housing slot 62. At this point the roller is no longer retained within the arcuate notch 64 of the driving head by surface 66 but is free to shift toward the restraining plate 28. Advantageously, the roller 60 projects outwardly of slot 62 by a distance less than its radius so that the driving force of head 22 readily cams the roller out of notch 64 and into recess 68 thereby automatically releasing the driving head 22 from support 26 and permitting its continued downward travel. By this action roller 60 locks support member 26 at the work station and prevents its inadvertent movement toward the retracted position of FIG. 1, it being appreciated that the interengagement of stop 30 and edge 38 provides only a oneway limit to movement of support 26.

As mentioned hereinbefore, the sealing jaws 48 are pivotally mountedon the fixed pin 50 carried by the support member 26 and therefore resist further downward movement as the piston continues its travel. However, the released drive head 22 and the toggle pin 56 carried thereby are free to move downwardly, the pin 56 traveling along an interior track 74 in the support member 26 and causing the toggle links 54 to pivot outwardly. The tops of jaws 48 pivotally connected to the toggle links correspondingly move outwardly causing rotation of the sealing jaws 48 about their fixed pivot pin 50 thereby effecting the desired seal-crimping action illustrated in FIG. 3.

As can be seen, the mechanism of the present invention thus smoothly accomplished the positioning of the sealing assembly 16 at a work station and the performance of the desired work function by smoothly interlocking and unlocking the necessary elements during one uninterrupted driving stroke of the tool. After completion of the sealing portion of the operating cycle, the flow of compressed air to the piston cylinder 42 is normally cut off, whereupon the return spring 40, which was loaded during the downward movement of the piston, comes into play to drive the piston back to its rest position. As the drive head 22 is drawn upwardly support member 26 is retained by roller 60 in its locked position relative to the frame. Therefore, the jaws 48 pivot about pin 50 to their open position until the toggle pin 56 strikes the upper limit of its track 74 and the mechanism assumes the position illustrated in FIG. 2. The notch 64 is once again in registry with slot 62 and the driving action of the toggle pin on the support member 26 earns the roller 60 into notch 64 thereby releasing or unlocking the support member 26 from the restraining plate 28 and interlocking the drive head 22 with the support 26 for continued upward movement toward the rest position of FIG. 1.

The invention thus provides a powered strapping tool with a highly efficient, simplified and durable sealing assembly drive transfer that eliminates the usual, troublesome and complex mechanisms heretofore needed to position and operate the sealing assemblies of strapping tools. The structure of the invention provides one, continuous, smooth and powerful piston stroke for first positioning the sealing mechanism at a work station and thereafter performing the desired work function with the full driving force of the piston behind it.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

lclaim:

1. In a device having a work-performing tool movable between a retracted rest station and a work station and operable in the work station for performing a work function, support means for the tool movable therewith into and out of the work station and tool drive mechanism including an actuator operable for moving the tool into and out of the work station and driving the tool through a work-performing operation, the improvement wherein the support means is provided with an aperture and the drive mechanism includes a releasable interlocking having a connector transferably positioned within the aperture and having a portion protruding outwardly therefrom, the actuator being provided with connector-receiving means for cooperatively receiving the protruding portion of the connector to releasably secure the actuator to the support means and thereby hold the tool in a nonworking condition during travel of the tool into and out of the work station, and upon reaching the work station being adapted to release the actuator for driving the tool through a Work-performing operation and automatically secure the support means against movement.

2. The device of claim 1 wherein the protruding portion of the connector is provided with anarcuate surface and the conhector-receiving means includes camming means acting on the arcuate surface to automatically effect release of the actuator upon movement of .the tool into the work station.

3. In a device having a work-performing tool movable between a retracted rest station and operable in the work station for performing a work function, support means for the tool movable therewith into and out of the work station and a tool drive mechanism including'an actuator operable for moving the tool into and out of the work station and driving the tool through a work-performing operation, the improvement wherein the actuator has an arcuate recess and the drive mechanism includes a releasable interlock securing the actuator to the support means to thereby hold the tool in a nonworkingcondition during travel of the tool into and out ofthe.

work station, and upon reaching the work station being adapted to release the actuator. for driving'the tool througha work-performing operationand automatically secure the support means against movement, said interlock including an arcuate member carriedby the support means and having a portion thereof positioned within the recess during travel of the tool'between'its rest and work stations and movable therefrom while the tool 'is within the work station.

4. In a device suited for sealably securing overlapping portions of strapping and'the like and having a work performing tool movable between a retracted rest station and a work station and operable in the work station for performing a work function, said tool including a set of rotatable jaws, support means for the tool including a side member pivotally supporting the jaws and movable therewith into and out of the work station and a tool drive mechanism including an actuator operable for moving. the tool into and out of the work station and.driving the tool through a work-performing operation, the improvement wherein the drive mechanism includes a releasable interlock. having a' releasable latch carried by the side member, said interlock securing the actuator to the support means to thereby hold the tool in a nonworking condition during travel of the tool into and out of the work station, and upon reaching the work station being adapted to release the actuator for driving the tool through a work-performing operation and automatically. secure the support means against movement, said actuator including a jaw drive head having a latch-contacting portion adapted to cooperate with the latch for releasably interlocking the drive head and the side member.

5. The device of claim4 wherein the side member is provided with an aperture adjacent the drive head and the latch is a transferable member positioned within the aperture and having an arcuate portion protruding outwardly therefrom and the latch-contacting portion is an arcuate latch receptor movable into registry with the aperture for transferably receiving the protruding portion of the latch for interlocking the drive head and the side member.

6. The device of claim 5 wherein the transferable latch.

member is a roller of greater diameter than the thickness of' directly drivingthe jaw drive head to both move the jaws into the work station and cause pivotal operation thereof while in the work station.

8. The device of claim 7 wherein the frame includes a latch contacting portion adapted to cooperate with the latch for an? tomatically securing the side member to the frame upon.

release of the jaw drive head.

9. The device of claim 8 wherein the side member. is provided with an aperture positioned intermediate the frame and:

the drive head, the latch is a transferable roller having av diameter greater than the thickness of the side member, said.

roller being positioned withinthe aperture and protruding therefrom to provide alternative engagement between. a cammableportion of .theroller and the latch-contactingportions of the drive head and the frame. 

